1. Field of the Invention
The invention relates to a method of overload control for the processor of the central control of a telecommunication system, more specifically a telephone exchange of the type commonly referred to as the Stored Program Controlled (SPC) type, which method comprises the following steps:
(1) determining the number of calls in build-up phase in a first period of a predetermined length; PA0 (2) determining the demand on the capacity of the processor of the central control in the aforesaid first period; PA0 (3) estimating the maximum number of calls in the build-up phase which the processor is capable of processing simultaneously in a second period of a predetermined length; PA0 (4) determining with each new offered call in the aforesaid second period whether as a as a result of the new call the instantaneous number of calls in the build-up phase reaches the maximum number of calls estimated in step (3); PA0 (5) accepting the offered call if the number of calls estimated in step (3) was not reached; PA0 (6) rejecting the offered call if the estimated number was reached; PA0 (7) repeating steps (1) to (6) in a subsequent first period evaluating calls in a subsequent second period.
2. Prior art
Such a method is known from the European Patent Application EP No. 096.937. In the aforesaid patent application it is suggested to derive the maximum number of (telephone) calls which may be processed in a given period from a combination of the number of calls which were being processed in a preceding period and the demand on the capacity of the central control in this period. This demand usually consists of two components: the processor of the central control has to perform telephony tasks in a narrow sense (taking up receiver, signalling, path finding, metering and so on) but also performs tasks of a more general, administrative nature such as making operative or blocking, subscriber connections, locating errors and processing errors and (traffic) measurements.